APPLICATIONS
Term-End Examination
December, 2OO7
CS-63 : INTRODUCTION TO SYSTEM
SOFTWARE
Time : 2 hours Maximum Marks ; 60
l. (a) Write regular expressions for I
(i) A set of strings including
{d, abd, cd, abcd}
(ii) A set of strings x's, y's and z's.
For example {xxx, xxy, xxz ...zzz}
(b) Write an algorithm that accepts as input a decimal
number and converts it into octal representation and
also draw the corresponding flow chart for the same .
(7)
(c) Consider the following set of processes which arrive
in the ready queue at the same time :
Process CPU time
P1 8
P2 T2
P3 7
P4 9
P5 4
Consider the following scheduling algorithms '
F'CFS, SJF and Round robin (quantum : 2)
find the average turnaround.time.
(ii) What is waiting time of each process for each
of the above scheduling algorithms ? Also, find
the average waiting time I
(d) Write a shell program to find whether a given
number is an Avogadro number or not 7
(e.s. 153 is Avogadro no. as 153 = 13 + 53 + g3)
2. (a) What are the important tasks performed during :
(6)
i) Lexical analysis
ii) Syntax analysis
ii) Semantic analysis
(b) What is the usefulness of context free grammar ?Explain with an example. (4)
3. (a) Describe how fixed records L/O and variable length (5)
(b) what are the main advantages of distributed
operating systems ? How are the fire system and the
protection supported in distributed operating
systems ?
4. (a) write UNIX commands for the following : (5)
(i) To change the password for a given user.
(ii) concatenate the contents of 3 files into a single
file.
(iii) To run a particular command at the given time.
(iv) To display hard disk space used.
(v) To display the lines that do not include the
given string.
(b) Illustrate and discuss with a diagram, the address (5)
mappings in a paging system and a segmented
system.
5.
(a)with the help of any GUl-based operating system, (4)
explain the major components of its environment.
(b) Explain the following concepts : (6)
(i) Symbol Table
(ii) Case Tools
(iii) 4 GLs